Waldo d



UNITED STATES PATENT OFFICE.

WALDO D. PUTNAM, OF BOSTON, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO WILLIAM H. WILKINSON, OF SAME PLACE.

DIE STOCK OR HOLDER.-

SPECIFIGATION forming part of Letters Patent No. 519,734, dated May 15, 1894.

Application filed November 7, 1893. Serial No. 490,323. (No model.)

To all whom it may concern:

Be it known that I, "WALDO D. PUTNAM, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain Improvements in Die Stocks or Holders, of which the following description is a specification.

My invention is particularly adapted for use in holding dies in screw-cutting machines, and consists of a cylindrical portion enlarged at the outer end for the reception of the die, and slotted longitudinally, to give it a yielding pressure upon the die, and to accommodate itself to the variations in the size of the die incident to the adjustment of its cutting edges, and also in a slitted ring to surround said enlarged portion of the cylindrical holdor, and compress it about the die, by means of a screw passing through lugs upon either side of the slit in the ring. A further improvement consists in enlarging the diameter of one portion of the spindle of the cylindrical holder and making the bore of the clutchsleeve, which slides thereon, of corresponding differences in diameter, for the purpose of preventing wear and consequent irregular movement of the die-stock when in use.

In the drawings forming apart of this specification, Figure 1 is a longitudinal sectional view of the die-stock with the die, the clamping ring and the clutch-sleeve in proper position. Fig. 2, is aside elevation of the stock and spindle with the clutch-sleeve and clamping ring removed. Fig. 3, is a front-end view of the die-stock, with the die in position and held by the clamping ring. Fig. 4, is an elevation of the clutch-sleeve removed from the die-stock spindle.

Referring to the drawings in which the same part of the device is designated by similar letters in each figure: A, is the cylindrical head or die-stock having a die socket B, at its outer end and a spindle C at the opposite end. Several slots S are out through the diesocket and a portion of the cylindrical head, to give a spring pressure upon the die D. The inner portion S of the slots S may be enlarged, to allow the chips cut from the screw blanks to fall out.

' R is the clamping ring slitted at g, and provided with lugs 1 upon either side thereof through which is a screw m, by which the said ring is drawn around the socket B after the die is in place. At the opposite side of the ring R, is a hole containing a conical pointed screw n, which may be forced into the tapering hole in the slotted side of the die D, for the purpose of adjusting the cutting edges (1 of the die, and also preventing the die from turning in the socket.

The spindle G, has a section of its length E, of larger diameter than the rest of the spindle. This is for the purpose of providing a greater bearing surface fora portion of the clutch-sleeve F, to prevent wear and uneven motion of the die-stock whilea screw is being out.

By means of lugs H, projecting from the rear end of the die-stock head and similar lugs H from the front end of the sleeve F,

the latter engages the former and holds the die-stock during the screw cutting operation. The advantage of this construction is, that while the screw is being cut the enlarged portion of the spindle gives a close-fitting,

firm bearing for the die-stock, and insures more perfect work, than heretofore obtained, and when the out screw is being withdrawn from the die, the enlarged portions of the bearing between the spindle and sleeve are separated, thereby giving sufiicient opportu- 8o nity for movement of the die-stock radially, to prevent the screw from binding in the die when withdrawn therefrom and being injured in consequence.

The die D shown in Fig. 3, is separated into several parts according to my improved method which is made the subject of another application; the several portions which contain the cutting edges of the die are illustrated as being separated by radial fractures chine, a cylindrical head, containing a diesocket in its outer end, at the opposite end, a supporting spindle which has sections of its length of diiferent diameters, and a clutchsleeve upon said spindle, havinga bore which is the counterpart of the spindle, and in too which the spindle is adapted to slide, wherebv the die-stock is engaged and held while the screw is being cut and is released when the cut screw is being withdrawn, substantially as described.

2. A die-stock for a. screw-cutting machine, consisting of a socket A surrounded by a slitted ring R and having a spindle provided with an enlarged portion E; a supporting sleeve F to be secured in the tail-stock; of the machine, and projecting lugs upon the op posed faces of said sleeve and. die-stock, subto stantially as described.

WALDO :o. PUTNAM.

Witnesses:

A. J. BURROW, '1. J. CUNNINGHAM. 

